Soldering Techniques?

[MountainMan]

Both temperature and humidity cause expansion, depending on the materials. Next time you drive over a bridge or on a concrete surface, notice the number and placement of the expansion joints. Concrete and steel are unaffected by humidity, but respond to temperature variances. You will also see expansion joints in brick buildings, as well.

I'm surprised that one of our more technically advanced members hasn't figured out a way to measure the expansion in his layout using altered conductivity or something.

I can't speak for other parts of the country, but a layout inside a building here in So Cal without some sort of skylight to allow for solar gain, just won't change that much. It will see temp changes if the building is uninsulated and not heated or cooled, but in a temperature controlled space, the temperature swing will probably be less than 20 degrees, and our humidity stays around 10% year round. On a really humid day we may get all the way up to 20%.

Same here - humidity in the 20's is a soggy day. Ambient temps of 100 or so, however, are not unusual at all.